Presser mechanisms for sewing machines



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Feb 24, 1959 M. 1.. WATERMAN PEssER MECHANISMSFOR SEWING MACHINES Filed Oct. 21; 1955 INVENTOR. Max L. Wa/erman T TORNEY Fig. l.

e State Pa 1Q Singer N. J. a fll'porationof New Jersey Application October-21,1955 Serial No. 541,944 1 Claim. c1. 112-236) The present invention relates to presser mechanisms for sewing machines and more particularly to a socalled quick-adjustment device for sewing machine presser mechanisms, i. e., a device by means ofwhich the compression of the spring that biases the presser bar toward the work-supporting surface may be more rapidly released, restored or adjusted to an intermediate position.

The primary object of the present invention is to provide a quick-adjustment device for a sewing machine presser mechanism that is convenient and easy to operate, thereby facilitating adjustment of the compression of the presser bar spring to secure the desired adjustment thereof. Further objects of this invention are to provide a presser quick-release device that is inexpensive, can be readily inserted into and removed from the sewing machine and can be used in existing machines, is durable, dependable and efiicient in operation, and is neat and attractive.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

Fig. 1 is a fragmentary head endview in elevation and partly in section of a sewing machine embodying the present invention.

Fig. 2 is a detail sectional view on an enlarged scale of the quick-adjustment device of the presser mechanism illustrated in Fig. 1.

Fig. 3 is a detail sectional view taken substantially on the line 33 of Fig. 2.

Fig. 4 is an elevational view of the sleeve portion of a modified form of the quick-adjustment device, with the bushing illustrated in phantom to show the operative relation of the parts. I

With reference to the drawings, there is illustrated a sewing machine head 1 overhanging a bed 2 having a throat plate 3. Feed dogs 4 which form a part of the feeding mechanism of the machine operate through the throat plate 3 in the usual manner to advance the work.

The work is pressed against the throat plate 3 and the feed dogs 4 by a presser foot 5 that is carried at the lower end of a presser bar 6 mounted vertically in the head 1 for axial sliding. The presser bar 6 is biased toward the throat plate 3 by av coil compression spring 7 that is wound around the presser bar. At its lower end the spring 7 bears against a collar 8 secured to the presser bar 6 by a set screw 9, the collar 8 having a rearward extending arm 10 that cooperates with the hand lifter lever 11 pivotally mounted on the head by a pivot screw 12.

At its upper end the presser bar telescopes into a sleeve 1 2,874,664 Ce Feb. 24, 1959 2 13 that is mounted for axialsliding movement in an externally threaded bushing 14 screwed into the top of the head.1 and having an enlarged'head 14a disposed abovethe top of 'thesewing machine head 1 to provide for. manually rotating the bushing 14 and thereby threading it into thev headl' of the sewing machine. The bushing 14 is locked in verticallyadjusted position by a lock nut 15. The'lower end of thesleeve 13 forms the adjustable abutment for the 'upper' end of' the spring 7. Th6' sleeve f13 is held against vertical movement une der the action of thespring 7 "by: a screw stud 16 that is threaded radially through the head14a' of the bushing 14 and has a smooth surfaced free end 16a that extends into a vertically inclined spiral slot 17 in the sleeve 13. The slot 17 is provided with landings 18 along its lower edge for receiving the stud 16 to prevent .turning of the sleeve 13 relative to the stud 16 due to the cam action between the stud 16 and slot 17 as the sleeve 13 is urged upwardly by the spring 7. The landings 18 are spaced along the lower edge of the slot '17 to provide a plurality of positions of adjustment between the maximum and minimum positions. There is therefore provision for variation of the compression of the spring 7 and the consequent force urging the presser bar 6 downwardly to obtain the optimum presser bar action for the particular sewing operation. Setting of the presser mechanism to determine the maximum and minimum positions of adjustment of the quick-adjustment device is made by adjustment of the bushing 14 in the head 1.

To effect a vertical adjustment of the sleeve 13 to relax the compression of the spring 7, the sleeve is depressed against the action of the spring, or it can be merely rotated, to remove the free end 16a of the stud 16 from the landing 18 in which it is then seated and rotating the sleeve until the stud is seated in the landing corresponding to the desired compression of the spring 7 and consequent presser action. The stud 16 willautomatically enter the selected landing18 when the sleeve 13 is released since the sleeve is urged upwardly by the spring 7. To compress the spring 7 it is necessary only to push the sleeve 13 down against the action of the spring 7, the sleeve being rotated by the cam action between the stud 16and the upper edge of the groove 17.

To facilitate pushing the sleeve down against the action of the spring 7, the upper end of the sleeve 13 has an enlarged head 19 that is counterbored to provide a flange 20 and a thumb button 21 is inserted into the end of the sleeve with the bottom edge thereof expanded to a diameter larger than that of the inner diameter of the flange 20. The button 21 is thus held against axial movement but is free to rotate so that when a force is applied against the button 21, as by the thumb of the operator, it will be transmitted to the sleeve 13 and urge the same downwardly, but the rotation of the sleeve 13 as it moves downwardly will not be transmitted to the button 21. Indicia 22 is provided on the enlarged head 19 of the sleeve 13 to indicate the setting of the quickrelease device, the indicia being provided to correspond with the landings 18.

In Fig. 4 there is illustrated a modified form desig- V nated 13a of the sleeve 13 in which the indicia 22a is is for purposes of illustration any and not to be con strued as a limitation of the invention. All such modifica on h h do not; depart f om. he sp r t 9 he e t on a e ntended to n t ud fl within h 9 1 O heappc ded cl im- Having thus set forth thenature of the invention, what'l aim h e n s A quick-adjustment device for the presser mechanism of a sewing machine comprising a bushing adapted to be threaded into the top of the head of a sewing ma chine and having an enlarged head adapted to be ar-, ranged above the head of 'the sewingmachine and having a bore extending axially. therethrough, an, adjustable spring abutment member mounted in the bore of said 15 2,534,651

bushing for rotation and for axial sliding movement, said abutment member having a spiral slot in the periphery thereof, a plurality of landings disposed along the lower edge of the spiral slot between the ends of said slot at preselected points corresponding to the desired settings for various particular sewing conditions, and a stud comprising a screw threaded radially through the head of said bushing and having a free end extending into the spiral slot in said abutment member.

References Cited in the file ofthis patent UNITED STATES PATENTS Corson Sept, 28, 1937 Scavelli et al. Nov. 21, 1939 Abos et al, Dec. 19, 1950 

